ESP8266 Community Forum

- Thu Jun 18, 2020 10:03 am #87574 Hi,

my ESP8266 is sometimes not waking up from deepsleep. But not always.

Now I have that state. When I plug in USB to "debug", I cannot see anything. How can I find, why it did not start up successfully in that state?

LED is not lit and battery (LiPo 4mAh seems to be absolutely enough power left)

Best regards,
Markus

- Tue Jun 30, 2020 10:53 am #87713 Hi Markus,

I'm not sure that I'm able to understand what you are trying to achieve. You have a ESP with your code running and you have entered the deep sleep mode in that code. Now you plug the device into your USB port and expect, that the chip leaves deep sleep mode? Why should it do that? Connecting the serial interface is not a wake up source for the ESP.
Or is it just that after connecting to USB the serial output of your code is not displaying in the PC's terminal? In that case you just may have to close and reopen the terminal after you plugged in the cable. Most people use an USB2UART converter to connect the ESP to the PC. If you unplug that, the port (COMx) will be removed from the windows device manager and the terminal will close the port. But if you plug it in again (and the port will return) the terminal will not automatically reopen the port...